The doctrine of election is scriptural if it is stated that God saves whom he wants and condemns those who sin. What more is there to say?
But if the doctrine of election is expanded to include notions of predestination and reprobation and human knowledge of either of these things or if it is worded in such a way as to make men and women believe that they can or do know such matters even if the knowledge appertains only to themselves then it is not in accord with holy scripture's general teaching and is a heresy.
The WCF says "The doctrine of this high mystery of predestination is to be handled with special prudence and care, that men, attending the will of God revealed in his Word, and yielding obedience thereunto, may, from the certainty of their effectual vocation, be assured of their eternal election. So shall this doctrine afford matter of praise, reverence, and admiration of God; and of humility, diligence, and abundant consolation to all that sincerely obey the gospel." and the underlined bold text in it is heretical.